This article argues for the possibility of aggressive akrasia, or the akrasia rooted in “unqualified knowingness.” The aggressive akratic acts knowledgeably and voluntarily for a bad end. Many philosophers reject the very possibility of aggressive akrasia given a prior commitment to closely identifying the will with practical reason, thereby effectively dismissing the possibility of an agent’s full responsibility for a morally evil act. Hence, these philosophers try to explain akrasia by challenging the voluntariness of the akratic’s action, or his knowledge, or both. Against one such view—that the akratic recognizes at least some rationality even within bad motivations—this paper contends that so long as the agent does indeed recognize the motive as a bad one, he cannot intelligibly appeal to it as the reason for his action. However rational an illusion may appear, if the agent knows it to be an illusion, he cannot intelligibly follow it. Hence this and other accounts fail to dismiss the possibility of aggressive akrasia.